On that night of July 16, 1918 – with the blessing of Bolshevik leader Vladimir Lenin – the bodies were then stripped and dumped in a truck. Before dawn the remains were driven away from Ekaterinburg, a remote town in Siberia. The plan was to dispose of them in a disused mine shaft. Instead, the truck threatened to break down. What to do?

The anxious executioners hastily dug a shallow grave, tossed the bodies in and, for good measure, doused them with blistering sulphuric acid. To guarantee that the victims were never identified, the killers drove the flagging truck back and forth over the damaged bodies, after covering them in the dirt of the new red Russia.

Such was the demise of the Romanov family – Tsar Nicholas II, Tsarina Alexandra, their son and four daughters – as well as three servants and the royal family's doctor. Or was it?

It's a question that's stirred personal, political and historical passion for years. And it's about to trigger an enormous ruckus in – of all places – Brisbane, the site of an international scientific conference. The fight hits town this week.

At issue will be a series of high-profile DNA tests conducted between 1991 and 1996, which confirmed that the bodies of Nicholas, Alexandra, three daughters and their retainers had at last been found. It fitted neatly with a claim by the leader of Lenin's firing squad that the bodies of a princess and the prince had been burned, not buried.

The Russian government accepted the findings and the remains were buried in 1998 – with due ceremony – in St. Petersburg. Case closed.

That is until early this year. In March, a separate research team published a paper with the unwieldily title, "Molecular, forensic and haplotypic inconsistencies regarding the Ekaterinburg remains". Rough translation: They aren't the Romanovs.

All hell broke lose, and scientists have been fighting bitterly ever since. Much to the surprise of Tom Loy, an expert in ancient residues with the University of Queensland. Both the it-is and the it-isn't camps will be represented at DNA 7, a conference on ancient DNA that Loy organised. Surprisingly, he didn't invite scientists from either side.

"They came to us," says Loy, director of the university's molecular archaeology laboratory. "We didn't ask either one, and both submitted papers." They are American molecular biologists Thomas Parsons of the Armed Forces DNA Identification Laboratory and George Washington University in Rockville, Maryland. And in the rival camp, Alex Knight of Stanford University in California.

Both scientists have analysed putative Romanov remains, bone and DNA. Each genuinely believes he is right and the other is utterly wrong. And they aren't shy in fighting their corner.

"Their results are too good to be true," says Knight of Parsons and his colleagues' work. "I'm sure Parsons has nothing to do with a conspiracy – that's way too farfetched – but those bones were contaminated."

To understand the import and heat it's necessary to return to the grim days of the Russian revolution. Six months after the Romanovs were executed, an avowed monarchist named Nikolai Sokolov investigated a probable grave. He found physical evidence but no skeletons. Sokolov's seven-volume dossier on his findings – never verified – became the basis of history's knowledge of the event, not to mention ongoing stories of missing bodies, lost identities and political conspiracies.

Then in April 1989, film-maker Geli Ryabov dropped a bombshell. He claimed he and geologist Alexander Avdonin had found the Romanovs' grave. Then president Boris Yeltsin gave the go-ahead, and in 1991 the remains of nine people were exhumed. Russian forensic experts confirmed that remains were the Romanovs. However, an American team disagreed with some of the forensic findings. To sort it out, tests were conducted on DNA extracted from the bones by a group headed by Russian scientist Pavel Ivanov and Peter Gill of the British Forensic Science Service.

The group analysed nuclear DNA – passed on by both parents – and mitochondrial DNA that is inherited only from mothers. Their conclusion: there was a family group of five, including three sisters.

They confirmed Alexandra's line was present by comparing mtDNA from remains believed to be hers with that of her grandnephew, Prince Philip, the Duke of Edinburgh. It matched.

A similar comparison of Nicholas's mtDNA was less clear-cut. "There was a slight twist and that's why I got involved," says Parsons.

Very simply, the wrinkle was that the living relatives had identical mtDNA, as expected. But Nicholas had a tiny mutation called a heteroplasmy that made his genetic fingerprint different at that one spot.

Parsons figured that a bit of mtDNA from the tsar's brother would tell all. So his team gained permission to analyse the skeletal remains of Grand Duke Georgij Romanov, buried in St Petersburg. They found a similar heteroplasmy and reported their finding in 1996, paving the way for the eventual reburial of the remains.

Meanwhile, Knight was busy studying human genetic variation, following the Romanov case only casually until a colleague brought it to his attention. "The more I learned about the case, I realised the impossibility of what these people were claiming, [given that] the bones were in terrible shape," he says.

Moreover, Knight believed there were so many irregularities at every stage of the discovery, exhumation and forensic investigation of the remains, that results obtained by the other teams – no matter how solid – would mean little. The "chain of custody" of the samples was just too dodgy.

So, working with American and Russian researchers, Knight attempted to replicate the earlier mtDNA findings. His group was permitted to extract DNA from a fingerbone of the Grand Duchess Elizabeth, sister of Alexandra, owned by a New York cleric. They found only the slightest similarity to that reported for the tsarina.

Their conclusions were damning. The people reburied with such pomp were unknown victims of the civil war. Worse, the material passed on to scientists such as Parsons had been contaminated with fresh DNA.

So who laced the bones with suspect DNA and why? "I cannot speculate," says Knight, confident that his presentation this week in Brisbane will not sit well with Parsons.

It won't. "The results are a complete fizzle," claims Parsons. "There's nothing to them. They have nothing to do with the Romanovs."

And the Romanovs themselves? They must be turning in their grave – wherever it may be.